Diamond drill and rock fragment excavation device

ABSTRACT

In a preferred embodiment of the invention, there is provided a subterranean cavern excavated by conventional methods and with conventional support structures and floor, with vertically extending shafts extending downwardly thereto for the removal of mining rock debree, and from the floor of the cavern there extend downwardly shaft-drilling downwardly facing diamond drill faces rotatably drillable of deep shafts into hard lithosphere earth and there extend between distal downwardly located terminal ends of parallel shafts of the downwardly facing diamond drill faces spaced apart from one-another a predetermined distance a laterally extending substantially horizontal tubular rotatable diamond drill having the drill bits of the tubular rotatable diamond drill arranged substantially helically along the tubular surface of the outer face of the tubular drill, there being defined within the downwardly extending drill shafts and within the bevel gear arrangment and within the horizontal tubular rotatable diamond drill a coolant flow path and structure defining the same, and there being apertures along the diamond drill bit outer surface of the horizontal tubular rotatable diamond drill for passage of the coolant therethrough to environment of the drilling diamond drill bits thereof, and the entire downwardly extending drills and horizontal drills being encased within a steam or other coolant-entrapment casing substantially totally segregating coolant vapor from environmental spaces for human being workers within the passages of the subterranean passages, and by conventional mechanisms the diamond drills being lowerable during the drilling operation as deeper drilling proceeds. There is also provided laterally horizontally extending conveyor belt mechanisms and rock fragment-removal mechanism for retrieving rock fragment to the conveyor belt which in turn delivers the same to collection vessels for conveyance to earth surface locations.

United States Patent [191 Baciu [451 May 13, 1975 [54] DIAMOND DRILL ANDROCK FRAGMENT EXCAVATION DEVICE [76] Inventor: Petru C. Baciu, 48-2048th St.,

Woodside, Queens, NY. 11377 [22] Filed: Jan. 23, 1974 [21] Appl. No.:435,697

2,563,913 8/1951 Binney 175/330 X 3,424,254 1/1969 Huff 175/17 3,460,8678/1969 Cameron et al. 299/2' 3,612,193 10/1971 Hirata 175/91 PrimaryExaminerErnest R. Purser [57] ABSTRACT In a preferred embodiment of theinvention, there is provided a subterranean cavern excavated byconventional methods and with conventional support structures and floor,with vertically extending shafts extending downwardly thereto for theremoval of mining rock debree, and from the floor of the cavern thereextend downwardly shaft-drilling downwardly facing diamond drill facesrotatably drillable of deep shafts into hard lithosphere earth and thereextend between distal downwardly located terminal ends of parallelshafts of the downwardly facing diamond drill faces spaced apart fromone-another a predetermined distance a laterally extending substantiallyhorizontal tubular rotatable diamond drill having the drill bits of thetubular rotatable diamond drill arranged substantially helically alongthe tubular surface of the outer face of the tubular drill, there beingdefined within the downwardly extending drill shafts and within thebevel gear arrangment and within the horizontal tubular rotatablediamond drill a coolant flow path and structure defining the same, andthere being apertures along the diamond drill bit outer surface of thehorizontal tubular rotatable diamond drill for passage of the coolanttherethrough to environment of the drilling diamond drill bits thereof,and the entire downwardly extending drills and horizontal drills beingencased within a steam or other coolant-entrapment casing substantiallytotally segregating coolant vapor from environmental spaces for humanbeing workers within the passages of the subterranean passages, and byconventional mechanisms the diamond drills being lowerable during thedrilling operation as deeper drilling proceeds. There is also providedlaterally horizontally ex tending conveyor belt mechanisms and rockfragmentremoval mechanism for retrieving rock fragment to the conveyorbelt which in turn delivers the same to collection vessels forconveyance to earth surface 10- cations.

DIAMOND DRILL AND ROCK FRAGMENT EXCAVATION DEVICE This invention isdirected to the drilling and excavation of rock deep in the lithosphereand below, by novel drilling and evacuation devices of the presentinvention.

BACKGROUND TO THE INVENTION Naturally occuring in nature, as one goesbeneath the earths upper surface, there eventually is encountered deeperearth in the form of very hot and very hard rock, with superificialearth layers thereabove as a cover in the form of sedimentary rockswhich have different composition and crystaline structure and aretypically cold rock soft in nature as compared to the deeper rock.Conventional drilling and mining drilling equipment is directed to anddesigned solely for and is effective solely in the drilling ofsedimentary rocks, for the drilling of sedimentary rocks of manydifferent physical characteristics as the crust of the earth; for suchcrust of the earth drilling there are accordingly many specialized newtypes of equipment for permitting mankind to penetrate into the earthsdepths. However, the excavation operation in hot and hard rocks of. andbelow the lithosphere constitutes one of the most formidable problems inthe mining field today, particularly with the ever increasing importanceof arriving at new sources of energy that might be associated with themining of such depths.

The continuous development of science and technical demands require newsolutions in all fields, together with the practical elements ofsimplicity, low cost of material, low cost of operation, and speed ofoperation, for thereby providing an economical solution.

The hot and very hard rocks of and below the lithosphere have very highdensity and a temperature much higher than the surrounding shallowerearths crust, the temperature of these deep rocks rising up to about1200F, or more, depending upon the age of the rock. Prior to the presentinvention, there has not been produced efficiently effective types ofequipment able to produce mined narrow excavated chambers by drilling topenetrate these hot, hard rocks. The urgent industrial needs of societyto build such narrow and long and deeper chambers demand as immediate,simple, and economical equipment and method producing such a minedexcavation by a novel approach which will permit the excavation of suchhot and hard rock without the physical presence of human laborers, andwithout polluting the hydrosphere, lythosphere, or atmosphere, andwithout complicated and/or costly equipment and without requiringnormally complicated and expensive cooling systems and equipmentnormally very difficult to build and normally very costly and thereforetotally uneconomical in the drilling of such chambers by any heretoforeconventional approach.

In the drilling at deep depths below the earth in the presence of theseelevated temperatures and in the drilling of such hard rock, thereclearly has to be effective cooling of the drill bits.

However, a problem with the use of coolant at these depths includes theready vaporization of most conventional coolants at these depths,particularly if water is utilized as an inexpensive coolant. In thepresence of steam so-produced, clearly there could be hazard to life.Also, there is the problem of removal of rock fragment when the coolanthas vaporized and therefore does not avail itself as a vehicle tocarry-away the rock fragments.

Accordingly, it may be now better appreciated the magnitude of thecomplexities of any efforts to design an equipment and process for theremoval of and excavation of these deep hot and hard rock by drilling.

SUMMARY OF THE INVENTION Accordingly, objects of the present inventioninclude the overcoming of one or more difficulties and problems of thetype discussed above, and the fulfilling of one or more needs of thetype discussed above.

Other objects become apparent from the preceding and followingdisclosure.

One or more objects of the present invention are obtained by theinvention as defined herein.

Broadly the invention achieves the object(s) by the employment ofparticularly designed diamond drill equipment together with speciallydesigned deep cavern structures, together with a conveying system andequipment therefor for the transport of the rock fragments from thedrilled areas.

More particularly the equipment and system include one or more uprightdownwardly extending supports supporting a laterally extending normallyhorizontal tubular drill having the drill diamond bits mountedpreferably helically along the outer tubular surface with the tubularelement being rotatable as the tubular element is permitted to pressdownwardly to engage and grind away the rock, there being apertureswithin the face of the tubular element through which coolant is passedfrom within the tube to prevent excessive heating-up of the diamonddrill bits which it should be noted are grinding solely on the lowerhalf of a revolution since the upper half of the revolution is not incontact with the rock. Preferably the support is at each end of thetubular element diamond drill and each support includes at its lower enda terminal drill face downwardly facing also of diamond drill bits withthe downwardly facing drill bits being rotatably ground downwardly intothe hard hot rock. It is important that the coolant flow be sufficientlygreat as to flow away and/or blowaway the rock fragments to a point towhich they may be gathered mechanically and transported mechanicallyfrom the site of drilling. Although there are possible other mechanisms,in a preferred embodiment of the invention, a large mass-bucket or boxdevice having bottom flap(s) which flip upwardly by any convenientmechanism such as for example by the pressure of the bucket or boxpressing downwardly into fluid slurry or mud to push upwardly theflap(s) to thereby fill within the bucket or box inner space defined bythe walls thereof, whereupon the flaps become pressed downwardly to aclosed state as the bucket or box is raised mechanically as by cables,the contents of the bucket or box thereby being raised with the bucketor box to thus be conveyed to a convenient point. In a preferred system,a horizontally extending floored cavern has been excavated inlow-temperature harder rock of the earth with conventional methods ofexcavation and support within the cavern, and from this subterraneancavity the deep drilling is performed. Accordingly there is provided aconveyor belt upon which the filled bucket or box is emptied such thatthe contents of fragmentary rock is conveyed to a larger vessel which isthereafter utilized to complete the trip of the rock fragments to theearths surface. Preferably the cabled bucket and/or box system andconveyor belt and vessel lift are each and all mechanically carried onin the ab sence of the actual presence of human beings within theoperating space by virtue of the presence of a segre= gating casingwhich is mounted flushly upon the upper cavern floor adjacent the pointat which the vertical downwardly facing drills and at which thehorizontally extending tubular drill cut a crevice-like slot downwardlyinto the hot hard rock, whereby the steam produced is totally isolatedfrom the areas of control by the workers, the steam being channeledupward through chimney structures of the casing.

Although water is a preferred coolant of the present operation becauseof low cost thereof, other coolants that might be desired and/orconventional are within the contemplation of the present invention,including one or more high boiling organic liquid coolants, for exampleof the type normally employed with nuclear reactors.

The diamond bits and mounting structure(s) therefor will be of thedesired and/or conventional type(s).

In a preferred embodiment of the invention, spaced apart downwardlyextending rotary shafts provide for plug drilling-out as well as providefor the support of the horizontally extending tubular element diamonddrill extending therebetween and supported between and by thespaced-apart upright drills, and the upright drills each preferablyrotate in drill fashion, and extend through a bevel gear apparatussecured operatively to the horizontal tubular drill with operativeconnection with the bevel gear mechanism by each of the upright drilland the horizontal tubular drill such that the rotary motion of theupright drive and support shaft is imparted to the tubular diamond drillelement to rotate it such that the helically arranged diamond bits alongthe outer tubular surface of the tubular drill rotatably drill into thehot hard rock therebeneath.

The invention may be better understood by making reference to thefollowing Figures.

THE FIGURES FIG. 1 illustrates a side cross-sectional view as takenthrough apartially drilled excavation employing the preferredembodiments of the present invention, illustrating the upper excavatedcavern extending horizontally and the elongated slots and holes drilleddownwardly therefrom, together with typical preferred rock fragmenttransporting equipment and earth surface derrick drilling towers.

FIG. 2 illustrates an elevation plan view of an installation at earthsurface of an embodiment typically as illustrated in FIG. 1.

FIG. 3 illustrates an elevation plan view of the installation of FIG. 2as it would appear devoid of the structures mounted on the surface ofthe earth.

FIG. 4 illustrates a view substantially corresponding to that of FIG. 1,after completion of the drilling thereof and after removal of thedrilling equipment, along FIG. 3 lines 4-4.

FIG. 5 illustrates a view as taken along lines 5-5 of FIG. 4, in anin-part view.

FIG. 6 illustrates an in-part view in side crosssectional view of theupright and horizontal tubular drills of FIG. 1.

FIG. 7 illustrates an in-part enlarged side view as taken along lines7-7 of FIG. 8.

FIG. 8 illustrates a side cross-sectional view in in -part view as takenalong lines 88 of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 through 8 all relate tothe same basic illustra' tion as best shown in its entirety in FIG. 1,some of the Figures being merely special views. Accordingly theinvention is hereafter described in general with regard to all Figures.

In cold or hot hard rock of and below the lithosphere, excavation may bemade without the need of reinforcing structures that are essential inconventional drilling and mining to prevent collapse of the wall; in thehot and hard rock to which this invention is directed, the rock is selfsupporting. Accordingly, it is necessary to build by conventionalmethods a shaft to the hot and hard rock, and according to a preferredembodiment of the invention to build by conventional methods andsupports the tunnel extending horizontally at the base of the shaft 30for the purpose of connecting consecutive wells 30a and the shaft, thetunnel being also for the facilitation of transport of excavated rockfragments toward the earths surface from the drilled hardrock chambersin accord with the present invention. Also, the tunnel makes possiblethe connection of consecutive upright downwardly facing diamond drillsoperatively with the bevel gearing and the interconnecting horizontallyextending tubular drill elements.

Self-supporting casing 30a is provided for the drilling well 3012.

The shaft 30 will be of conventional construction and materials built byconventional methods, and will include passenger elevator 49, elevator14 for hoisting rock fragments by motor 45, cables 39 for hoistingcollection vessel 11 enclosed within conduit 29 extending upwardlywithin the shaft 30, cable 43 for hoisting the elevator 14, automaticmeasurement instruments and control lines (not illustrated) ofconventional types together with conventional pressurized air conduits,light lines, drinking water lines and safety equipment and the like areare conventional. Tunnel 31 is excavated at the base of shaft 30extending in opposite lateral directions horizontally built byconventional method at a size best suited for the operations to beperformed at any given point therein, such as the connection of thetubular upright diamond drills 3 and the horizontal interconnectiongtubular diamond drills 6 connected by bevel gears 5 for the drivingthereof from the rotation drills 3. Also extending horizontally withinthe tunnel 31 is the conveyor 12, together with an associated hoppertypically including an archimedy-type screw conveyor extending from thehopper 13 to the elevator 14 to be filled. Casing 28 serves to channelupwardly the steam 27 in a segregated state from worker personnel spacesof the tunnel 31.

The excavation installation with diamonds as described above is achievedby two or more drilling bit apparatuses depending on the length of theexcavated chambers, but may consist of a single unit if desirable.

With particular reference to FIG. 1, the composite parts illustrated,for example, include the derrick drilling towers l equiped with swivels2, and other conventional materials such as lifting hooks, cables,cranes, etc., and rotary tables 8, and engines 7 for driving the rotarytables 8, upright drills 3 with the lower portion connected bevelconnecting portion 33 connected optrated a diamond cutting'blockincludingthe portion 33 having water passage and exit therefor throughthe continuing passages of the bevel gears and horizontal drill 6. Itmay be seen that the cutting downwardly directed diamond bit face ofdrill 4 is of sufficient diameter or breadth as to permit easy insertionin the drilled passage the bevel gears'S and casing 9.

It is necessary to" mention that at the bevel gear mechanism 5 andcasing 9 one or both will include obviously a convention type plug ofthe coolant flow conduit in the direction in which there is absent anyfurther tubular drill at each of opposite terminal end portions of aninstallation, in order to prevent uncontrolled flow and loss of coolant.

FIG. 6 illustrates ih'enlarged in-part view in crosssection theoperational relationship of the conical bevel interacting gears 5 havingsteps 36 thereof, and the horizontal diamond tubular drills passage 35and associated apertures37 for coolant flow to the diamond bit cuttingsurfaces and the diamond cutting bits 38. This coolant water exitingthrough apertures 37 also serves to facilitate removal of the rockfragments from the.

surface of and vicinity of the cutting diamond bits and to produce aplastic mass or mud loadable therby into the collection vessel 11. Thewater is fed from an outside reservoir source 17, and after passagethrough apertures 37 in the vicinity of collection vessels 11 whenlowered evaporates and is vented to atmosphere in the segregating casing28; there are water return pipes 24 however for water to clarifying tank25, and water bypass conduit (conventional in nature) 26 between tank 25and reservoir 17, and reservoir outlet and pump inlet pipe 18 and pump19 and pump outlet pipe 20, and branch feed pipes 21 connected to thecoolant passage of drill tubular pipe 3 for feeding coolant through thelower portion 33 coolant passage into thelower drill 4 (conventional innature) through apertures in its lower face andinto the horizontaltubular drill passage 35. The coolant water serves to cool the drillingdriving tubes as ,well as the drill diamond bits.

The water in its cooling and lubrication circuit absorbs the heatgenerated from the friction of the drilling pipes and the diamond bitswith surrounding rock as well as the rocks latent heat. If the watersources are not sufficient for necessary cooling, then the water vapors27 can be condensed and introduced again in the water-cooling circuit.During the initial period at the the excavation when the hard rock isnot hot enough for the evaporation of the water from within thechambers, the evacuation of the water and mud from the chambers 32 isdone with the mud pump 23 placed in the tunnel 31, mud suction conduit22 being directed downwardly to the mud source, and pump outlet 24leading upwardly, and leading to the clarifying tank 25, etc..

ling diamond bits is principally effected by the elevator vessels It, byelevator cables 39, pulleys 40, electric winches 41 placed on the earthssurface, and the like.

In FIGS. 1 and 8, the elevator vessel 11 and its hinged bottom openableupwardly as botton 42 are viewable. The hinged bottom 42 of the elevatorvessel 11 opens during the downward penetration of the elevator vesselinto the plastic mud of rock fragments, and closes due eratively todrive bevel gearsS typically within a casing The evacuation of theexcavated material by the drilto gravity and downward weight of contentsupon the raising'of the vessel 11 by the supporting cables.

In FIGS. 1 through 4 and 7 and 8, there is viewable the entire systemfromdifferentviews, such as of tunnel 31, wells 30a, shaft 30, steamsegregating casing 28, steam exhaust conduit 29, and condensor 29afeeding into receiver 17 by conduits 29b. 7

By desirable and/or conventional means already well known to technology,all of this activity will be watched and controlled automatically and/ormanually principally from a central control room 48 and panel includingtypical pressure, temperature, power, and television sensors and thelike, with appropriate electronic circuitries therefor and for theautomatic control of the activities to be carried on by the cables,conveyors, drills, pumps, etc.

During the advancement of the excavation in both sedimentary and hardrocks, there are provided the necessary drilling tubular drill pipes andpieces and replacement bits, casings, and the like. The typically wouldbe provided and outside warehouse for such, as warehouse 50.

OPERATION On the ground there is set up rotary tables 8 with engines 7,with the tables having their upright support aligned with the respectiveshafts 30, with the drive engines 7, with an equal number of drillingpipes 3 spaced apart equally along the ground surface, with the supportdrilling tower for each, as towers 1. The swivels 2 are connectedfor thewater, and then the water is introduced into the drilling pipe 3 eachequiped with the downwardly directed drilling bit 4. Drilling of uppershaft 30, wells' 3a and excavating of the tunnel 31 is conducted inaccord with known mining procedures and methods employing standardmaterial and parts. Below the floor of the cavern tunnel 31, drillingproceeds utilizing the system already described above, utilizing thesespecially designed drilling bit combinations and system, for thedrilling of the hot and hard rock. The bit 4 is aligned coaxially withthe axis of the drill tube 3. Then the operation is automaticallystarted as follows.

The engines 7 begins driving the rotary tables 8 and thereby driving thedrilling pipes 3 and intimate diamond bits 4, and through the bevel gearmechanism 5 the tubular diamond cutting bit 6 is driven in a horizontalposition to cut downwardly a slot into the hard hot rock.

The coolant water and/or steam quickly produced produces a mud plasticmass which is pumped upwardly by pump 23 by mud inlet 22 and pump outlet24. The elevator vessels 11 load and transport mud-like rock fragmentsupwardly and clumps the same onto conveyor belt 12 which delivers thesame to the hopper with the archimedytype screw conveyor into transportvessel(s) 14 for conveyance to ground level. The vessel 11 is dumped byinverting action of cables 39a and 39b as shown in FIG. 8. The towershaft structure 46 by pulley mechanisms 44 and cables 43 lift theelevator collection vessel 14 upwardly for delivery of its cargo (astypically by a downwardly opening bottom not illustrated of anyconventional type) into a conveyor train hopper car 15 which transportson tracks 47 to a storage bin 16 for excavated rock fragments. Duringthe initial period when the mud pumps are most necessary, all elevators11 must work continually because the speed of the water circulation inthe chambers 32 does not assure the mud evacuation of all the chips bythe diamond bits. This eliminates substantially the possibility of anyblocking of the installation by plugging. During the working operationof the excavation with the diamond drills, it is necessary to watch veryclosely to ascertain that the automatic system should maintain the speedand the advance of all the drilling pipes 3 at the same value andperfect synchronizing operation. This condition is necessary in order toobtain the effect synchronized cutting by both the vertical bit 4 andthe tubular horizontal bit 6 such that the bevel gears and casing 9 donot become blocked. The vertically extending drill tubes 3 in thesedimentary rocks as well as in the zone of the hard rock areconstructed and operated by conventional means except the preferredcoolant passages in the drilling face 4 thereof. Drill-pipecentering-sleeves will be mounted in spaced vertical relationships toone-another along the drilled channel 32a.

The mining works, the equipment, the geological conditions(characteristics) of the hot and hard rock, shown in the above combinedtechnology, allows a new method of high efficiency which can producenarrow chamber, long and deep, channels, trenches, and galleries in thehot and hard rocks, offering this way a new weapon for an inexpensiveand simple way of excavation even in the most unbelievablecircumstances.

In FIG. 4, one can see the whole excavation in the sedimentary rockszone as well as the hot and hard rock. Narrow chamber 32 and 32aresulting from the downward drilling by the horizontal drills 6 andvertical drill 4 are defined by substantially smooth and cleanself-supporting walls, of the hot hard rock, complying with allnecessary technical requirements.

There preferably is a linear (coaxial) relationship between consectivealternately located horizontal drill tube 6.

It is within the scope and spirit of the invention to makemodifications, and substitution of equvalents within ordinary skill ofan artisan in this field.

I claim:

1. A rock drilling device comprising in combination: a tubular elementhaving inner and outer tubular surfaces and defining a plurality ofcoolant-flow apertures through the tubular walls of the tubular elementwith the apertures defining a coolant flow path from within the tubularelement to laterally exterior thereof, the apertures extendingsubstantially radially outwardly from the longitudinally axiallyextending tubular coolant flow path within the tubular element, therebeing diamond cutting bits arranged along the outer tubular surfaceswith the apertures substantially adjacent the diamond cutting bits, andbevel gear means and drive shaft means with the drive shaft meansextending along its longitudinal axial axis at an angle laterallyrelative to the tubular elements longitudinally axially extending axisand the shaft means being operatively connected through the intermediatebevel gear means for revolvable with and fixedly secured to a terminalend of the longitudinally extending drive shaft means with the diamonddrilling face extending in a direction substantially transverse to thetubular elements longitudinally axially extending axis, the diamonddrilling face having an area of drilling effectiveness at least as greatas a cross-sectional area of the drive shaft means, and

a second drive shaft means and a second bevel gear means and a seconddiamond drilling face each mounted at an opposite end of the tubularelement operatively substantially the same as the other drive shaftmeans, the other bevel gear means and the other diamond drilling face.

3. The rock drilling device of claim 2, and vaporizable coolant andtubular means for channeling the coolant to the tubular element, and inwhich the tubular means for the coolant extends concentrically within atleast one of the drive shaft means and through the bevel gear meansoperatively to communicate with the tubular elements coolant flow path.

4. The rock drilling device of claim 3, and power drive means fordriving the drive shaft means, and extension support means forsupporting the drive shaft means and for extending the same downwardlyas drilling proceeds, and encasing means for segregating vaporizedcoolant from surrounding human beinginhabitable environment and forchanneling the vaporized coolant to a location away from the drillingsite,

and rock fragment-removal means for collecting rock fragments fromrock-drilled sites and conveying the same to a rock elimination locationaway from the drilling site, and substantially horizontally extendingsubterranean passage-defining cavern means defining space and horizontalfloor structure and conveyor means extending substantially horizontallyalong the cavern means space, the conveyor means being for receivingrock fragments from the rock fragmentremoval vessels, and includingremoval vessel means with removal vessels transportable of rockfragments contained therein from the cavern means to a location atsubstantially the earths surface.

1. A rock drilling device comprising in combination: a tubular elementhaving inner and outer tubular surfaces and defining a plurality ofcoolant-flow apertures through the tubular walls of the tubular elementwith the apertures defining a coolant flow path from within the tubularelement to laterally exterior thereof, the apertures extendingsubstantially radially outwardly from the longitudinally axiallyextending tubular coolant flow path within the tubular element, therebeing diamond cutting bits arranged along the outer tubular surfaceswith the apertures substantially adjacent the diamond cutting bits, andbevel gear means and drive shaft means with the drive shaft meansextending along its longitudinal axial axis at an angle laterallyrelative to the tubular element''s longitudinally axially extending axisand the shaft means being operatively connected through the intermediatebevel gear means for driving rotatably the tubular element around thetubular element''s longitudinally axially extending axis as a result offorce transmitted by the drive shaft means to and through the bevel gearmeans, and the tubular element being supportable by the bevel gear meansand the bevel gear means being supportable by the drive shaft means. 2.The rock drilling device of claim 1, in which said diamond cutting bitsare arranged substantially helically in a longitudinally axiallyextending direction along the outer tubular surfaces, and a plugdrilling shaft means including a diamond drilling face rotatablyrevolvable with and fixedly secured to a terminal end of thelongitudinally extending drive shaft means with the diamond drillingface extending in a direction substantially transverse to the tubularelement''s longitudinally axially extending axis, the diamond drillingface having an area of drilling effectiveness at least as great as across-sectional area of the drive shaft means, and a second drive shaftmeans and a second bevel gear means and a second diamond drilling faceeach mounted at an opposite end of the tubular element operativelysubstantially the same as the other drive shaft means, the other bevelgear means and the other diamond drilling face.
 3. The rock drillingdevice of claim 2, and vaporizable coolant and tubular means forchanneling the coolant to the tubular element, and in which the tubularmeans for the coolant extends concentrically within at least one of thedrive shaft means and through the bevel gear means operatively tocommunicate with the tubular element''s coolant flow path.
 4. The rockdrilling device of claim 3, and power drive means for driving the driveshaft means, and extension support means for supporting the drive shaftmeans and for extending the same downwardly as drilling proceeds, andencasing means for segregating vaporized coolant from surrounding humanbeing-inhabitable environment and for channeling the vaporized coolantto a location away from the drilling site, and rock fragment-removalmeans for collecting rock fragments from rock-drilled sites andconveying the same to a rock elimination location away from the drillingsite, and substantially horizontally extending Subterraneanpassage-defining cavern means defining space and horizontal floorstructure and conveyor means extending substantially horizontally alongthe cavern means'' space, the conveyor means being for receiving rockfragments from the rock fragment-removal vessels, and including removalvessel means with removal vessels transportable of rock fragmentscontained therein from the cavern means to a location at substantiallythe earth''s surface.